1. Field of the Invention
The present invention relates to phase detecting methods, and more particularly to phase detecting methods for detecting BPSK (binary phase shift keying) modulated data by analog-to-digital conversion.
2. Description of the Prior Art
Generally, it is known that various types of data signals may be superimposed on a television broadcasting signal prior to the television broadcasting signal being transmitted. Such information signals may include analog television signals as well as a variety of digital data signals, for example, teletext, time code, caption data, etc. In the case of digital data, there are a variety of methods for superimposing the data signal on the broadcasting signal. Such modulation techniques may include, for example, FSK (frequency shift keying), BPSK (binary phase shift keying), NRZ (nonreturn to zero) or PSK (phase shift keying). The digitally modulated broadcasting signal is then transmitted as an analog signal. A receiver receives this analog signal and demodulates the received analog signal in order to extract the corresponding digital data. In the demodulating process, it is important that the data be accurately extracted.